The GPR method is a wave propagation technique that transmits and receives electromagnetic waves (EM or radio waves). We have used GPR ground imaging for mapping underground utilities, karst features such as cavities and voids, soil and/or rock layer thickness, fractures in bedrock, lava tubes, underground storage tanks (UST), detecting old foundations, and mapping debris or other obstacles to construction. Borehole GPR applications include: soil profile imaging, karst, imaging of embedded concrete or steel structures (e.g., piles), fault identification, quantification of fracture density and orientation in rock, and detection of other utility-like features (pipes, tanks, etc.).